%% This is file `fbox.sty'
%%
%% Copyright (C) 2019, ..., 2023
%% Herbert Voss  <hvoss@tug.org>
%%
%% It may be distributed and/or modified under the
%% conditions of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%% The latest version of this license is in
%%    http://www.latex-project.org/lppl.txt
%% and version 1.3c or later is part of all distributions of LaTeX
%% version 2005/12/01 or later.
%
% $Id: fbox.sty 828 2023-12-04 19:56:29Z herbert $
%
% -------------------------------------
\ProvidesPackage{fbox}[2023/12/04 v. 0.07 allow parts of the frame (hv)]
%
\RequirePackage{xkeyval}
\RequirePackage{xcolor}

\newlength\fbox@@rule
\newlength\fbox@@sep
\newlength\fbox@@linewidth
\define@key{fbox}{boxrule}[0.4pt]{\setlength\fbox@@rule{#1}}
\define@key{fbox}{boxsep}[3pt]{\setlength\fbox@@sep{#1}}
\define@key{fbox}{bcolor}[black]{\def\fbox@bcolor{#1}}
\define@key{fbox}{tcolor}[black]{\def\fbox@tcolor{#1}}
\define@key{fbox}{lcolor}[black]{\def\fbox@lcolor{#1}}
\define@key{fbox}{rcolor}[black]{\def\fbox@rcolor{#1}}
\define@key{fbox}{linewidth}[\linewidth]{\setlength\fbox@@linewidth{#1}}
\setkeys*{fbox}{boxrule=\fboxrule,boxsep=\fboxsep,
  lcolor,rcolor,bcolor,tcolor,
  linewidth=\linewidth}

% latex.ltx
%\fboxsep = 3pt
%\fboxrule = .4pt

\let\orig@fbox\fbox
\def\fb@lowerc@se#1{%     make \lowercase expandable
  \begingroup\edef\x{%
    \lowercase{\endgroup\def\noexpand\@tempa{#1}}}\x
}
%
\newif\if@fbox@star
\newif\if@fbox@space@left
\newif\if@fbox@space@right

\long\def\fbox{\@ifnextchar*{\@fbox@startrue\FBox@}{\@fbox@starfalse\FBox@*}}
\def\FBox@*{\@ifnextchar[\FBox@i\orig@fbox}
%
\def\FBox@i[#1]{%
  \def\XKV@rm{}%
  \setkeys*{fbox}{boxrule=\fboxrule, boxsep=\fboxsep, #1}%
%  \typeout{===>#1:  \XKV@rm}%
  \if@fbox@star
    \@fbox@space@leftfalse
    \@fbox@space@rightfalse
  \else
    \@fbox@space@lefttrue
    \@fbox@space@righttrue
  \fi
  \expandafter\ifx\expandafter\relax\XKV@rm\relax
    \@tempcntb=15
  \else
    \@tempcntb=\z@
    \expandafter\fb@lowerc@se\expandafter{\XKV@rm}%
    \expandafter\FBox@ii\@tempa\@nil\relax
  \fi
  \FBox@iii
}
\def\FBox@ii#1#2\@nil{%
  \ifx#1t\advance\@tempcntb by 8                %  top
  \else
    \ifx#1l\advance\@tempcntb by 4              % left
      \if@fbox@star\@fbox@space@lefttrue\fi
    \else
      \ifx#1r\advance\@tempcntb by 2            % right
        \if@fbox@star\@fbox@space@righttrue\fi
      \else
         \ifx#1b\advance\@tempcntb by 1         % bottom
  \fi\fi\fi\fi
  \if\relax#2\relax\def\next{}\else\def\next{\FBox@ii#2\@nil}\fi
  \next
}
\def\FBox@iii#1{%
  \leavevmode
  \setbox\@tempboxa\hbox{%
    \color@begingroup
      \if@fbox@space@left\kern\fbox@@sep\fi{#1}\if@fbox@space@right\kern\fbox@@sep\fi
    \color@endgroup}%
  \@FrameB@x\relax}
%
\def\@FrameB@x#1{%
  \@tempdima\fbox@@rule
  \advance\@tempdima\fbox@@sep
  \advance\@tempdima\dp\@tempboxa
  \hbox{%
    \lower\@tempdima\hbox{%
      \vbox{%
        \ifnum\the\@tempcntb>8\relax
          \advance\@tempcntb by -8 
            {\color{\fbox@tcolor}\hrule\@height\fbox@@rule}%                       % top
        \fi
        \hbox{%
          \ifnum\@tempcntb>3
            \advance\@tempcntb by -4 
            \textcolor{\fbox@lcolor}{\vrule\@width\fbox@@rule}%
          \fi                                             % left
          #1%
          \vbox{%
            \vskip\fbox@@sep
            \box\@tempboxa
            \vskip\fbox@@sep}%
          #1%
          \ifnum\@tempcntb>1\textcolor{\fbox@rcolor}{\vrule\@width\fbox@@rule}\fi}% right
          \ifodd\@tempcntb{\color{\fbox@bcolor}\hrule\@height\fbox@@rule}\fi%     bottom
        }%
    }%
  }%
}

\newsavebox\fpar@b@x

\long\def\fparbox{\@ifnextchar*{\@fbox@startrue\FParBox@}{\@fbox@starfalse\FParBox@*}}
\def\FParBox@*{\@ifnextchar[\FParBox@i\FParBox@ii}
\long\def\FParBox@i[#1]#2{%
  \setkeys*{fbox}{linewidth=\linewidth,#1}%
  \savebox\fpar@b@x{\parbox{\dimexpr\fbox@@linewidth-2\fbox@@sep-2\fbox@@rule}{#2}}%
  \FBox@i[#1]{\usebox\fpar@b@x}}
\long\def\FParBox@ii#1{%
  \setkeys*{fbox}{linewidth=\linewidth}%
  \savebox\fpar@b@x{\parbox{\dimexpr\fbox@@linewidth-2\fbox@@sep-2\fbox@@rule}{#1}}%
  \orig@fbox{\usebox\fpar@b@x}}
  
  
\endinput